How would I connect these up...?
First, make sure you're in pose mode with your armature. Then, still in Pose mode:


Select both your eye's lattice objects (it will turn back on object mode, no worries)
Shift select the head's bone (it should switch automatically to pose mode, otherwise do it manually)
Hit CtrlP → Set parent to Bone


This way your lattices are following the head's bone.

The only remaining advice I would give you is to use a constraint Child Of on your C_look_target bone, to make it parented to the head's bone.
That way, the eyes, and their target will follow the head, as well as the lattices, which is usually more practical to use when posing.
When you will need to move the head while the eyes target stay still, simply animate the Child Of influence parameter from 1 to 0, and vice versa when you need the opposite behavior.